Effects of Survivin Antagonists on Growth of Established Tumors and B7-1 Immunogene Therapy

• Published in: JNCI : Journal of the National Cancer Institute Vol. 93; no. 20; pp. 1541 - 1552
• Main Authors: Kanwar, Jagat R., Shen, Wei-Ping, Kanwar, Rupinder K., Berg, Randal W., Krissansen, Geoffrey W.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 17.10.2001; Oxford Publishing Limited (England)
• Subjects: Animals; Antibodies, Monoclonal - administration & dosage; Apoptosis; B7-1 Antigen - administration & dosage; B7-1 Antigen - therapeutic use; Biological and medical sciences; Chromosomal Proteins, Non-Histone - antagonists & inhibitors; Chromosomal Proteins, Non-Histone - biosynthesis; Chromosomal Proteins, Non-Histone - genetics; Chromosomal Proteins, Non-Histone - physiology; Combined Modality Therapy; Disease Progression; DNA, Antisense - administration & dosage; DNA, Antisense - genetics; DNA, Antisense - therapeutic use; Female; Gene Dosage; Gene Expression Regulation, Neoplastic; Gene Targeting; Genes, Dominant; Genetic Therapy; Genetic Vectors - administration & dosage; Genetic Vectors - therapeutic use; Graft Rejection - immunology; Immunotherapy; Inhibitor of Apoptosis Proteins; Injections, Intralesional; Lymphocyte Depletion; Lymphocyte Subsets - immunology; Lymphocyte Subsets - pathology; Lymphocytes, Tumor-Infiltrating; Lymphoma, Non-Hodgkin - drug therapy; Lymphoma, Non-Hodgkin - immunology; Lymphoma, Non-Hodgkin - pathology; Lymphoma, Non-Hodgkin - therapy; Medical sciences; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Neoplasm Proteins - antagonists & inhibitors; Neoplasm Proteins - biosynthesis; Neoplasm Proteins - genetics; Neoplasm Proteins - physiology; Neoplasm Transplantation; Other treatments; Survivin; T-Lymphocytes, Cytotoxic - immunology; Thymus Neoplasms - immunology; Thymus Neoplasms - pathology; Thymus Neoplasms - therapy; Treatment. General aspects; Tumors; Thymus gland; Rodentia; Malignant hemopathy; Survivin; Costimulatory molecule; Plasmid; Vertebrata; Mammalia; Treatment; EL4-Lymphoma; Mouse; Apoptosis inhibitory protein; Lymphoproliferative syndrome; Animal; Immunotherapy; Established cell line; Antagonist; Gene therapy
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/93.20.1541

Background: Survivin, a member of the inhibitor of apoptosis (IAP) protein family, is detectable in most types of cancer, and its presence is associated with a poor prognosis. We determined the effects of gene-based therapies that inhibit survivin function in a mouse tumor model. Methods: Using five to six mice per treatment group, we injected tumors derived from mouse EL-4 thymic lymphoma cells with plasmids encoding antisense survivin, a dominant-negative mutant survivin, and the T-cell costimulator B7-1. Expression of endogenous survivin and the proteins encoded by the injected plasmids were examined by immunohistochemical staining of tumor sections and by western blot and flow cytometry analyses of isolated tumor cells. Tumor growth, the generation of antitumor cytotoxic T-lymphocyte (CTL) activity, apoptosis, and the contribution of leukocyte subsets to antitumor activity were measured. All statistical tests were two-sided. Results: Large (1.0-cm diameter) tumors had approximately 10-fold more survivin than small (0.2-cm diameter) tumors. At 28 days after injection, antisense and dominant-negative mutant survivin plasmids statistically significantly inhibited the growth of both small (P = .006 and P = .0018, respectively) and large (P<.001 for both plasmids) EL-4 tumors compared with tumors injected with empty plasmid. The growth of large tumors was further inhibited by intratumoral injection with antisense survivin and B7-1 (P = .004); thus, inhibition of survivin expression renders large tumors susceptible to B7-1-mediated immunotherapy. Mice whose tumors were completely eradicated by injection of B7-1 remained tumor free for 26 days after re-injection with EL-4 cells (when the experiment ended). Compared with tumors injected with empty plasmid, tumors injected with survivin-based plasmids had increased apoptosis, and animals bearing such tumors generated more antitumor CTLs. Conclusion: Intratumoral injection of plasmids that block survivin expression and stimulate the generation of tumor-specific CTLs may be beneficial for the treatment of large lymphomas.